Enzymes of carnitine acylation. Is overt carnitine palmitoyltransferase of liver peroxisomal carnitine octanoyltransferase?
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چکیده
منابع مشابه
Malonyl-CoA inhibition of peroxisomal carnitine octanoyltransferase.
Although the malonyl-CoA sensitivity of peroxisomal carnitine octanoyltransferase (COT) is reportedly lost on solubilization, we show that malonyl-CoA does inhibit the purified enzyme. Assay conditions such as buffer composition, pH, acyl-CoA substrate and the presence or absence of BSA can affect the observed inhibition. When assayed in the absence of BSA, COT shows simple competitive inhibiti...
متن کاملStructural Model of the Catalytic Core of Carnitine Palmitoyltransferase I and Carnitine Octanoyltransferase (COT)
Carnitine palmitoyltransferase I (CPT I) and carnitine octanoyltransferase (COT) catalyze the conversion of longand medium-chain acyl-CoA to acylcarnitines in the presence of carnitine. We propose a common threedimensional structural model for the catalytic domain of both, based on fold identification for 200 amino acids surrounding the active site through a threading approach. The model is bas...
متن کاملEffects of fasting and malonyl CoA on the kinetics of carnitine palmitoyltransferase and carnitine octanoyltransferase in intact rat liver mitochondria.
There has been considerable interest in the observation that the overt form of carnitine palmitoyltransferase (CPT1) in liver mitochondria is potently inhibited by malonyl CoA [I ,2]. It has been suggested [2] that this is a competitive type of inhibition against long chain acyl CoA substrates. However, this is based upon measurements of ketogenesis [3-51 or indirect calculations of CPT, activi...
متن کاملCarnitine palmitoyltransferase II deficiency
The authors investigated 32 patients with the muscle form of CPT II deficiency. Total carnitine palmitoyltransferase enzyme system (CPT) activity was normal but abnormally inhibited by malonyl-CoA, palmitoyl-CoA, and the detergents Triton X and Tween 20. Mutation analysis identified three described mutations (S113L, P50H, and F448L) and two novel mutations (M214T and Y479F). Using modeling tech...
متن کاملThe soluble carnitine palmitoyltransferase from bovine liver
The properties of two carnitine acyltransferases (CPT) purified from bovine liver are compared to confirm that they are different proteins. The soluble CPT and the inner CPT from mitochondria differ in subunit Mr, native Mr, pI and reactivity with thiol reagents. All eight free thiol groups in soluble CPT react with 5,5'dithiobis-(2-nitrobenzoate) in the absence of any unfolding reagent, and ac...
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ژورنال
عنوان ژورنال: Biochemical Journal
سال: 1988
ISSN: 0264-6021,1470-8728
DOI: 10.1042/bj2490231